1. Field of the Invention
The present invention relates to an ink jet printer of the type in which a plurality of ink jet print heads and a plurality of ink cartridges for supplying ink to the print heads are mounted on a carriage movable in the widthwise direction of a printing medium, and the print heads eject ink drops of different colors onto a printing medium in accordance with print data, to thereby print characters and images on the printing medium. More particularly, the invention relates to the technique of replacing ink cartridges.
2. Related Art
A recording device (referred to simply an a printer) with an ink jet print head has the following advantageous features: relatively low noise is generated at the time of printing, and small dots are formed at high density. Because of these features, the print head is used in a variety of printings inclusive of a color printing. Particularly, with the features of a further improvement of recording density and the capability of the color printing, an ink jet print head in which a black ink print head and a color ink print head are mounted on the carriage is put into practice. To reduce the size of the printer and simplify the ink supplying system, the printer is constructed such that ink cartridges for respectively supplying a black ink and colored inks to the print heads are mounted on the carriage.
When the ink cartridges of this type are attached to the carriage, air enters the passages of the print heads through their connection parts. To prevent air from entering, in a printer of the type in which two ink cartridges are mounted on the carriage, the ink cartridge which is to be replaced with a new one is specified by operating a related switch on a panel of the case of the printer, and a negative pressure is applied to the print head, to forcibly charge and discharge ink to and from the print head.
The specifying of the replaced ink cartridge depends on the user""s switch operation, if the user mistakenly operates the switch, ink is not charged into the new ink cartridge and the printer fails to print or ink is charged into the ink cartridge that was not replaced, resulting in a wasteful use of ink.
To solve these problems, an ink jet printer is proposed in Japanese Patent Laid-Open Publication No. Hei. 7-323576, for example. The printer includes an ink cartridge replacement history judging means for detecting an attaching of the ink cartridge by use of a signal derived from an ink cartridge detecting means. When the attaching of the ink cartridge is detected, ink is charged into the replaced ink cartridge.
The proposed printer succeeds in that it allows the ink to be charged into only the replaced ink cartridge, and inhibits the ink from being sucked from the ink cartridges that are not replaced. However, the user per se must specify the ink cartridge to be replaced. Therefore, idle attaching/detaching operations of the ink cartridges are inevitably performed. The result is the entering of air bubbles into the print head and defective printing.
The ink jet printer is constructed such that a pressure generating chamber pressurizes the ink to discharge the ink from a discharge orifice. Because of this construction, during shipping the printer must be placed in the same condition as when the printer is operated. To this end, the ink cartridges of the printer are filled with a liquid for shipping, to thereby prevent the print heads from being dried and clogged with dust.
For this reason, an initial charging operation is required. In this operation, the shipping liquid is completely removed from the ink cartridges before the first use of the printer, and the ink is charged from the ink cartridge into the associated print head such that the bubbles are completely removed from the print head. A process that is to be carried out when the ink cartridges are first attached to the printer delivered from the factory is performed by the user. Therefore, there is a possibility that the ink is erroneously charged. If the ink charging is erroneous, the printer will fail to perform a normal printing operation, as a matter of course. If the power supply is interrupted during the ink charging operation, the ink charging operation stops in the midst of the charging operation. To return the half-charged state of the print head to its original state, the user must do a complicated restoring manipulation. If he or she fails to correctly perform the manipulation, there is a danger that the recovery from the half-charged state is impossible.
According to the present invention, an ink jet recording device comprises an ink jet print head for ejecting different color ink in the form of ink drops; ink cartridges for supplying the ink to the print head; a carriage on which the print head and the ink cartridges are mounted; capping means for sealing the print head, the capping means being located outside a print section; suction means for applying a negative pressure to the capping means; a window allowing the ink cartridges to be exposed in a replaceable fashion; a switch being externally operable; and control means for moving only the ink cartridge to be replaced to a position confronted with the window in a replaceable fashion. With such a construction, when an ink cartridge or cartridges are to be replaced, only the ink cartridge that is to be replaced is selected and automatically moved to a replaceable position.
Accordingly, a first object of the present invention is to provide an ink jet recording device with ink cartridges which provide a simplification of the cartridge replacing work and succeed in eliminating erroneous cartridge replacing operations.
A second object of the present invention is to provide an ink jet recording device which automatically executes an initial ink charging operation to make the recording device ready for printing.
A third object of the present invention is to provide an ink jet recording device in which, even if the supply of electric power is interrupted during the cartridge replacing operation, a process necessary after the power supply interruption is automatically executed in response to the restart of the power supplying, and ink is charged into the print head to make the recording device ready for printing.